1. Field of the Invention
Embodiments of the present invention relate to electric lawn mowers that may be used outdoors for mowing grass or the like.
2. Description of the Related Art
Known lawn mowers generally include a mower body and a handle. The mower body is typically provided with wheels. The handle extends obliquely upward in a rearward direction from the mower body. The user may grasp the handle and push the mower body to move the same for performing a lawn mowing operation. The mower body may have a cutting blade that is rotatably driven by an electric motor as a drive source. In general, the motor is disposed within the mower body with its axis oriented in the vertical direction. The cutting blade rotates within a horizontal plane about the motor axis at a position along the lower surface of the mower body. Therefore, changing the vertical position of the wheels relative to the mower body can change the cutting height or the mowing height. EP0829196A2 (also published as Japanese Patent No. 3160759 and U.S. Pat. No. 5,910,091), U.S. Pat. No. 5,806,374 (also published as Japanese Patent No. 3329654), U.S. Pat. No. 5,736,837 (also published as Japanese Patent No. 3553277) and EP1285568A1 (also published as Japanese Patent No. 3776772 and U.S. Pat. No. 6,658,829) teach various techniques regarding electric lawn mowers.
In addition to electric lawn mowers driven by an AC power source, there have been proposed DC powered electric lawn mowers that can use batteries serving as DC power sources. When a DC powered electric lawn mower is used, the user does not need to lug a long power cord, and therefore, the performance (usability) in handling the lawn mower outdoors may be improved and the mowing operation can be efficiently performed. The battery may be removed from the tool body for recharging by a battery charger, so that the battery can be repeatedly used.
In recent years, battery packs having a battery case and a plurality of lithium-ion battery cells disposed within the battery case have been broadly used as batteries for power tools, etc. Therefore, there have been proposed electric lawn mowers having lithium-ion battery packs as power sources.
However, battery powered electric lawn mowers still require further improvements. For example, the battery pack may have a relatively large size. It may be as large as the electric motor. The battery pack needs to be protected from vibrations of the electric motor. Some electric motors are vertically oriented and end up transmitting large amounts of vibration to other areas of the lawn mower. It is preferred that such lawn mowers reduce such transmission while also retaining the ease with which the battery pack may be mounted or removed, for example, during recharging of the battery.
Therefore, there has been a need in the art for electric lawn mowers that enable the battery to be easily mounted and removed while protecting the battery from potentially dangerous vibrations transmitted from the electric motor.